I entered a help request to our ASE and got the following reply:
"We've received multiple reports of this error message this morning. We believe this to be a side effect of the code patch that we pushed out last night. The engineering team has been notified and is investigating this as we speak. I am keeping close tabs on this and will keep you updated on our progress here. Apologies for any inconvenience this may cause in the meantime."
For those that would like to be notified of when we fix issues like this, please note we have the Maintenance Updates that can be found in the bottom right of the Workfront One page, or you can bookmark it here:
Note the "Maintenance Update (Hot Fix) on July 17, 2020" addresses this specific issue.